Source : Free On-Line Dictionary of Computing

Tree Transformation Language
     
         (TXL) A hybrid
        {functional language} and {rule-based language} by Jim
        R. Cordy  et al of {Queen's University},
        Canada in 1988.  TXL is suitable for performing source to
        source transformations and for rapidly prototyping new
        languages and language processors.  It uses {structural
        transformation}.  It is written in {ANSI C}.
     
        It has also been used to prototype specification languages,
        command languages, and more traditional {program
        transformation} tasks such as {constant folding}, {type
        inference}, source optimisation and {reverse engineering}.
     
        TXL takes as input an arbitrary {context-free grammar} in
        extended {BNF}-like notation, and a set of show-by-example
        transformation rules to be applied to inputs parsed using the
        {grammar}.
     
        Latest version: 7.4, as of 1993-08-04.
     
        {(ftp://ftp.qucis.queensu.ca/pub/txl/)}.
     
        ["TXL: A Rapid Prototyping System for Programming Language
        Dialects", J.R. Cordy et al, Comp Langs 16(1) (Jan 1991)].
     
        ["Specification and Automatic Prototype Implementation of
        Polymorphic Objects in Turing Using the TXL Dialect
        Processor", J.R. Cordy & E.M. Promislow, Proc IEEE Intl Conf
        on Comp Lang ICCL'90 (Mar 1990)].
     
        (1993-08-04)